This invention related to barricade structures for streets and highways and more particularly to such barricades which comply with the requirements of the Manual on Uniform Traffic Control Devices for Streets and Highways issued by the U.S. Department of Transportation, Federal Highway Administration. Specifically, the DOT Manual describes two types of barricades with which the present invention is concerned; namely, Type I which is intended for use on conventional road or urban streets, and Type II which is for use on expressways, freeways or other high speed roadways. The difference between the two types is that the second type requires more reflective area. Type I can use a single reflective panel from 8 to 12 inches in height, for example, whereas Type II requires two such panels.
Past barricades have posed a number of problems in meeting such desirable objectives as portability, durability, reflective efficiency, as well as safety to a vehicle's occupants and persons in the work area whenever the barricade is struck by a fast moving vehicle. Any attempt to achieve all or nearly all of these objectives usually resulted in one or more of them being sacrificed by the promotion of the other. For example, in attempting to achieve durability the element of safety upon vehicular impact is often sacrificed. A wood or steel construction or a combination of these along with plastic, although durable, would prove extremely hazardous to the car, its occupants, and workmen in the area if hit by a vehicle, for example. On the other hand, a barricade that promoted safety and portability--a lightweight plastic construction, for example--might not be durable and might even fail to meet the requirements of DOT in not providing enough reflective area, that is, disposing the entire reflective area on a vertical plane which is normal to the traffic flow on a given street or highway. Such lightweight structures often resorted to the use of reflective panels disposed across the pivotal supporting legs so that reflective efficiency was impaired on two counts; (1) the reflective surface was angled away from the road surface as much as 30 degrees, thereby substantially reducing the brilliance of the retro-reflexive light from the reflecting surface, and (2) the effective width of an inclined 8 inch panel will not be the 8 inches required by DOT, that is, an 8 inch height normal or at right angles to traffic flow.